package com.ggkt.domain;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.concurrent.ConcurrentHashMap;

public class Demo {
    public static void main(String[] args) {
        Student stu = new Student("a0",20);
        ArrayList stuList = new ArrayList();
        stuList.add(0);
        for(int i = 0;i<10;i++){
            stuList.add(i);
        }
        HashSet stuSet = new HashSet();
        stuSet.add(0);
        for(int i = 0;i<10;i++){
//            stu = new Student("a"+i,20);
            stuSet.add(i);
        }

        ConcurrentHashMap chashMap = new ConcurrentHashMap();
        chashMap.put("1","java");
        chashMap.put("1","php");
        chashMap.put("2","c++");

        for(Object obj:chashMap.values()){
            System.out.println(obj);
        }
        System.out.println(chashMap.size());
    }
}
